Tuesday's clash between 14-time winners Real and Bayern, with six Champions League titles, is the most played semi-final in the competition's history.
England midfielder Bellingham, still just 20, joined Real Madrid before the start of the season from Bundesliga side Borussia Dortmund.
Bellingham has since become one of Real's most important players and is already considered among the world's best. He is their top goal scorer in the league this season with 17 goals, despite playing mostly as midfielder.
Tuchel said Bellingham was "a key player in a very offensive position" for the Spanish giants.
"Jude is extraordinary. He was fantastic here in the Bundesliga, how he progressed shows the level of personality he has, it's only possible with a huge personality.
"Everyone who plays for Madrid plays with the pressure of the shirt. He plays with the pressure to play with this club and all the expectations.
"He handles it like he's never done anything else," said Tuchel. "But we are well aware of it and will try and find solutions tomorrow (Tuesday)."
Home atmosphere
Tuchel has urged the home fans to create a special atmosphere at the Allianz Arena.
"We need the atmosphere to be incredible. We also need the fans to support us, even in moments when it's more difficult. Together with the fans, we need to create an atmosphere that gives us an advantage," he told reporters.
"When you're playing against Real Madrid, you're also up against the aura, the legend that surrounds them. Our focus will be fully on the game. We're all looking forward to a great match.
"(Madrid have) clear patterns. It's a mix of a midfield diamond and two holding, two attacking midfielders. It's very flexible, experienced and automated."
Tuchel will have a few injury doubts to key players going into the clash, including 21-year-old playmaker Jamal Musiala, who has 12 goals and seven assists across all competitions this season.
"As of right now, nothing is 100% certain," the German said.
"Konrad Laimer, Matthijs de Ligt and Dayot Upamecano will undergo some final checks soon. Things look good for Konni (Konrad). We also need to wait and see with Jamal Musiala and Leroy Sane."
Joshua Kimmich said the focus remains on putting Bayern in the best possible position for the second leg at Santiago Bernabeu on May 8.
"It's a clash between two big clubs. We know that Real have a lot of experience and quality in their team. They believe in themselves and know their strengths," the midfielder added.
"Nevertheless, we're heading into the game with plenty of confidence ourselves. We put in two good performances against Arsenal and have no reason to hide."